Scoliciosporum curvatum
Thallus effuse, composed of small green granules up to 50 µm diam., at first scattered but soon coalescing to form a thicker thallus. Photobiont cells 7-12(-15) µm diam.
Anamorph: not known.
Teleomorph: ascomata apothecial. Apothecia usually abundant, 0.1-0.16 mm, disc rounded, flat when young but soon becoming convex to hemispherical, sometimes contiguous and fused in well-developed specimens, pale to orange, becoming brown in old specimens. Exciple only visible in young apothecia. Epithecium and hypothecium colourless. Paraphyses abundant only in young apothecia, simple or furcate and rarely anastomosing. Ascospores 8-16 per ascus, fusiform, with acute ends, curved or lunate to slightly sigmoid, 1-septate, 7-11(-14) × 1.5-3.5 µm.
Woods & Coppins (2012) indicate an IUCN threat category of Least Concern and a restricted distribution designation of Nationally Scarce.
The minute pale brown apothecia often grow in abundance on evergreen leaves. Microscopic examination is required for confirmation; the lunate ascospores are distinctive.
The minute pale brown apothecia are most likely to be confused with Bacidia chloroticula (which also occurs on evergreen leaves) and microscopic examination is required for confirmation. This species is generally discovered when what appears to be an algal crust is carefully examined with a hand lens.
Known at present from scattered sites, mainly in SW. England, N. to S. Wales, S.W. & N.E. Scotland and N. Ireland. In recent years it has been found, rarely, in the English Midlands (Derbyshire and Warwickshire).
On the leaves of evergreen shrubs such as Buxus, Camellia and Rhododendron, in sheltered and humid sites. A minute and easily overlooked foliicolous species often growing along the leaf midrib of evergreen shrubs. On the Continent it has been found on the needles and twigs of coniferous trees.